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I'm struggling to run oprofile on my system because of an annoying error:

$ sudo opcontrol --setup --vmlinux=/usr/lib/debug/lib/modules/`uname -r`/vmlinux
$ sudo opcontrol --start
ATTENTION: Use of opcontrol is discouraged.  Please see the man page for operf.
Using default event: CPU_CLK_UNHALTED:100000:0:1:1
Using 2.6+ OProfile kernel interface.
Reading module info.
Failed to open profile device: Device or resource busy
Couldn't start oprofiled.
Check the log file "/var/lib/oprofile/samples/oprofiled.log" and kernel syslog

Anyone familiar with Oprofile will notice I'm using the proper sequence of commands to invoke the service. This comes directly from Fedora documentation. Kernel debug information was also installed to generate the appropriate vmlinux file. But even after passing the location of this file to oprofile, nothing chaged:

$ sudo opcontrol --setup --vmlinux=/usr/lib/debug/lib/modules/3.12.11-201.fc19.x86_64/vmlinux
$ sudo opcontrol --start
ATTENTION: Use of opcontrol is discouraged.  Please see the man page for operf.
Using default event: CPU_CLK_UNHALTED:100000:0:1:1
Using 2.6+ OProfile kernel interface.
Reading module info.
Failed to open profile device: Device or resource busy
Couldn't start oprofiled.
Check the log file "/var/lib/oprofile/samples/oprofiled.log" and kernel syslog

What's more is there's no log file in the specified location. I've tried several other solutions, including re-installation, deleting the daemon, and running without profiling the kernel.

  • Why is the device busy when there's no oprofile processes running?
  • Why is there no log file written?
  • What do I change so that I can run oprofile?
jdmartin86
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1 Answers1

2

Before running the oprofile, you should check wether your system exists watchdog. watchdog/nmi_watchdog registers with the perf subsystem which will blocking oprofile from working. You may have to stop the watchdog/NMI watchdog to free up counter 0 using the following:

echo "0" | sudo tee /proc/sys/kernel/watchdog

OR

echo "0" | sudo tee/proc/sys/kernel/nmi_watchdog

kukka
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